VulnerabilityPublished 21 Jul 2025

CVE-2025-51403: livehelperchat · A Stored Cross-site Scripting (XSS)

Affects livehelperchatSource CVE Database V5

Public exploit available (Exploit-DB) · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.5% chance of exploitation in 30 days – higher than 75% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 21 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
1 Exploit-DB entry, 1 day after disclosure
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by MITRE Corporation
16 Jun 2025, 35 days before disclosure
CVE published
on cve.org
21 Jul 2025, t = 0
In Threat Radar
record ingested
21 Jul 202519:16 UTC, the same day as disclosure
First Exploit-DB entry (opens in a new tab)
LiveHelperChat 4.61 - Stored Cross Site Scripting (XSS) via Department Assignment Alias Nick Field
22 Jul 2025, 1 day after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHublivehelperchat/livehelperchat`pkg:github/livehelperchat/livehelperchat`Other threats	Affected =4.60	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should immediately audit their Live Helper Chat installations to determine if version 4.60 or related versions are in use. Until an official patch is released, organizations should implement strict input validation and output encoding on the Alias Nick parameter to prevent malicious script injection. Employing a web application firewall (WAF) with rules to detect and block XSS payloads targeting this parameter can provide a temporary protective layer. Administrators should also review and restrict access to the department assignment editing module to trusted personnel only, minimizing the risk of malicious input. Monitoring logs for unusual activity related to this module can help detect attempted exploitation. Additionally, organizations should prepare to apply patches promptly once available and consider isolating or disabling the vulnerable module if feasible. User awareness training for support staff about phishing and suspicious behavior can reduce the risk of social engineering attacks leveraging this vulnerability.

Description

A stored cross-site scripting (XSS) vulnerability in the department assignment editing module of of Live Helper Chat v4.60 allows attackers to execute arbitrary web scripts or HTML via injecting a crafted payload into the Alias Nick parameter.

Impact

For European organizations using Live Helper Chat, particularly those deploying version 4.60 or similar, this vulnerability poses a significant risk to the confidentiality and integrity of their communications. Live Helper Chat is often used for customer support and internal communication, meaning that exploitation could lead to unauthorized access to sensitive conversations, customer data, or internal operational information. Attackers could leverage this vulnerability to execute malicious scripts that steal session cookies, enabling account takeover of support agents or administrators. This could further lead to unauthorized data access or manipulation, undermining trust and potentially violating GDPR requirements concerning data protection and breach notification. Additionally, the stored nature of the XSS means that multiple users could be affected over time, increasing the potential damage. The availability impact is generally limited for XSS, but indirect effects such as reputational damage, loss of customer trust, and regulatory penalties could be severe. Since no known exploits are currently reported, the threat is more theoretical but should be treated proactively to prevent future exploitation.

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

Timeline

What to do

Affected software

Description

AI analysisMachine-generated, updated 21 Jul 2025, 19:31 UTC

Public exploits and detection1 Exploit-DB entry

WeaknessesCWE-79

Technical details

References

Community reviews

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